The organic diols are useful as intermediates in the preparation of diol dicarbamate compounds which are widely used in the dye industry and for medicinal purposes. U.S. Pat. Nos. 2,837,560 and 2,848,459 disclose the use of alkane and aryl diols as intermediates in the preparation of alkanediol dicarbamates and aryldiol dicarbamates respectively.
U.S. Pat. No. 2,848,459 discloses the preparation of arylpropanediols wherein an ester of an aryl acetic acid, such an benzoylacetic acid, prepared by condensing benzoic acid ester with an ester of acetic acid, employing a basic substance, such as sodium ethoxide, as a catalyst is treated with a chlorinating agent, such as sulfuryl chloride, to yield benzoyldichloroacetic acid, ethyl ester.
Benzoyldichloroacetic acid, ethyl ester is subsequently reduced to 2,2-dichloro-1-phenyl-1,3-propanediol by reduction with lithium aluminum hydride in anhydrous ether.
Similarly, U.S. Pat. No. 2,884,444 discloses the preparation of 2-phenyl-1,3-propanediol by reduction of the corresponding 2-substituted malonic ester, diethyl phenyl malonate, with lithium aluminum hydride in ethyl ether. 2-phenyl-1,3-propanediol is an intermediate in the synthesis of 2-phenyl-1,3-propanediol dicarbamate an important anticonvulsant known generically as Felbamate.
The preparation of 2-phenyl-1,3-propanediol following the prior art methods i.e., by reduction of diethyl phenyl malonate with lithium aluminum hydride in ethyl ether as taught in U.S. Pat. No. 2,884,444 gives yields ranging from a low of about 30% of product to a high of only about 50% of 2-phenyl-1,3-propanediol.